We can agree to disagree. I'm certain your fish are healthy and happy. Nobody here suggested that fish be kept in a tiny tank, under 5 gallons. I was merely indicating what my search results offered.

For a 12 inch fish, I do doubt that a 5 gallon tank would be adequate to hold more than it's tail. The generally accepted rule of thumb is 1 inch of fish per gallon of water. Any less and the fish may very well starve for oxygen or suffer from disease. In this case, yes, a 55-60 gallon tank would be "just" sufficient. Some more demanding fish may require more than what 1 gallon can supply them, and in this case, 1 inch per 2-3 gallons may be called for.

While we may disagree with what others post, do the research yourself if you have indepth questions.

Sneakypete, I'm sorry if I hurt your feelings, as the tone of your posts suggest. I am a huge stickler for acurate facts, and I will spend HOURS researching one angle in order to find accurate information. The site you mentioned sounds like a good resource, and one I may look into for future questions.

Hi Yes,
I am also a very strong stickler of not just facts: but tried, tested, and true facts!!
All my fishkeeping has been accompanied by hours, not 10-12 but THOUSANDS
of hours of research.
I could walk with you into a pet store and identify and give requirements of most fish in the stores.
I can tell you about the nitrogen cycle, what filters work best in certain situations, how to do filter cleans and water changes step by step, and about many of the diseases and problems encountered in freshwater aquarium keeping.
I am a professional student not just by experience but nature, and believe learning is the most important task we were put on earth for. It really steams me when people cannot even bother to research the facts and then start spouting off at the mouth.
The biggest problem though is with the individual pet stores. The employees are hired for looks and retail experience, and not for knowledge of pets/fish/or fishkeeping. They still believe fish like Goldfish and Irridescent sharks belong in Aquariums, and in small ones to boot.
Most people's fish keeping knowledge is still stuck in the 1950's, and I cannot handle that kind of ignorance.
People think just because it is a "fish" that is has no feelings, cant feel pain, cant think, and are basically worthless.
To Me a fish is every much a pet as my dog or cats.
It is no different. If my fish hurts, I help to ease the pain. If it is sick, I try to heal it, and most importantly, I provide the best possibly life my fish could ever want to have next to being in the wild, where they will live their full life spans out, in Clean water, with heavy good quality filtration and a wide range of high quality fish foods, and fresh foods from the garden and the earth, as well as frozen foods to supplement their diets.
For me, to see a goldfish in a 5G tank, or a Betta in a "vase" is the exact same to seeings a puppy chained in a yard for every day of its life.
Animal cruelty shouldnt be limited to the animals we can pet and hold, but to all the animals we keep.
Their lifes depend on us, and it is up to us to give them that life. Happy healthy and fullfilled.
And people who are unwilling to do the work and the hundreds to thousands of hours of reading, research, conversation, and exploring that is needed to do so, should re-examine why they keep their pets. Are they for status? For Look? For Aesthetics? Or are they valued members of your family, right down to the finned, feathered, or furred members, each and every one?
If the answer is no....well I think you can tell what you should do.
Thank You.

Sneakypete, I commend you for doing your research thoroughly before you acquired a pet, any pet! More people should do their research, regardless if what they are getting is a fish, bird, cat, hamster, dog, etc. Every person who is considering getting a pet should do extensive research to determine whether or not that pet is the right one for them and their family. If more people took the time and researched, less animals would be given up or abused.

I agree, fish have feelings just like every other living creature does. I had a couple of Jumbo Pacus that were great fish. They recognised our family members, particularly the ones that maintained their aquarium and fed them daily. They let us know through their body language if they were content or if something was upsetting them. I loved all my fish. It hurt when they passed. I also believe that individual fish has unique personalities, just like other animals.

I also agree that most people you find in pet stores selling fish know very little about their upkeep. I don't agree with keeping fish in a small tank or bowl or vase. That is why I only every owned medium to large aquariums and would never go smaller.